New Manic Mechanic High Comp Billet Head

It's obviously a little more involved than I thought, but in terms of combustion chamber size, they can be easily compared.

Along those lines, they could be compared with a comp gauge on a given engine, just as my stock head and billet head can be compared. 115psi vs 142psi

My questions have only been for the benefit of others, as a comparison between mine, (RSE billet) and the new one. Mine suits me, as I said. My only drama, as you remember was stud length, hence that question.

Does it need quite as much fin area? Mine is pretty meaty and runs at a pretty good temp. I'm thinking overhead clearance issues with some frames.

Tony doesn't give a psi figure, quite rightly it seems, but he does give a CR figure of 16:1.

I've never delved deeply into this stuff in the past, beyond shaving about 0.040" off a few heads when I was younger, with no idea of any figures when I was done.

I learn more every day here.
And potential customers know a lot more about the impending head.

I was a bit blunt earlier and owe a bit of an apology. Maybe even a whole one.
Wouldn't be the first time and probably won't be the last.

... Steve
 
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Steve,

Lots of hours went in to the development of this head. Here are some more detailed pics of the process..

8-1.jpg

11.jpg

12.jpg

13.jpg

14.jpg


Justin
Pirate Cycles
 
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have any speed results in kmh of what ur 66cc bike would do both b4 and after jack drive conversion .


it a pity i dont have a compression tester i wonder what my 50cc rse hp1 motor with ceramic piston an billett parts all ova ......its ported an goes to 64kmh not bad with a 44 rear ...


brad
 
Steve,

Lots of hours went in to the development of this head. Here are some more detailed pics of the process..
Justin
Pirate Cycles

I don't doubt that, Justin. Looking pretty good, overall.
I'll wait until someone (with a comp gauge) bolts one onto a stock 66cc motor to find out a direct psi comparison. Only out of curiosity.
My remaining minor point is the height, which will prevent fitting this head to some engines, due to clearance issues. Otherwise, the extra meat and fins will help with cooling.
Love the workshop and bench, I use my dining room table for my engine work.

Brad, if you have 26" wheels, (I allowed for 25.6" under load), then at 64kph, (40mph), you're pulling about 9470RPM. Not too shabby.
Probably not good to hold those revs for too long at a time, though.

... Steve
 
Steve,

Good evening from sunny Florida. Here are a few answers to your questions, from the manufacturer.

"Looks different. It's very tall.
Again, what's the compression in psi?
That's more important than the sound, which is really the carb & pipe, not the head.
Also, what is the clearance, head/plug to piston?
And, does it bolt straight on with standard 107-108mm studs?

... Steve"


The overall height is decieving to the eye...it's actually only 1/8" taller than the cast piece measured vertically. If the engine is mounted at the typical 45 degree angle, the builder will need to allow an extra 1/2" for frame clearance. As Rich stated, the psi, relative to a compression gauge test is not accurate. Porting will affect the gauge reading. The cylinder head that I make has a chamber that is 1cc smaller than the factory head. Obviously, without any other modifications, the cylinder head that I make will show a higher reading on a compression gauge. This has been done for the current factory run of PK80 engines. Yes I know they aren't actually 80cc. Yes...of course I made it to fit as a direct replacement...The stock stud length was taken into consideration when designing the product.

Tony at Rock Solid is a friend, a customer, and a pro engine builder...I'm not making cylinder heads to compete with him. I'm making them for a specific engine that Pirate Cycles sells.

Jim
 
Steve,

Good evening from sunny Florida. Here are a few answers to your questions, from the manufacturer.

"Looks different. It's very tall.
Again, what's the compression in psi?
That's more important than the sound, which is really the carb & pipe, not the head.
Also, what is the clearance, head/plug to piston?
And, does it bolt straight on with standard 107-108mm studs?

... Steve"


The overall height is decieving to the eye...it's actually only 1/8" taller than the cast piece measured vertically. If the engine is mounted at the typical 45 degree angle, the builder will need to allow an extra 1/2" for frame clearance. As Rich stated, the psi, relative to a compression gauge test is not accurate. Porting will affect the gauge reading. The cylinder head that I make has a chamber that is 1cc smaller than the factory head. Obviously, without any other modifications, the cylinder head that I make will show a higher reading on a compression gauge. This has been done for the current factory run of PK80 engines. Yes I know they aren't actually 80cc. Yes...of course I made it to fit as a direct replacement...The stock stud length was taken into consideration when designing the product.

Tony at Rock Solid is a friend, a customer, and a pro engine builder...I'm not making cylinder heads to compete with him. I'm making them for a specific engine that Pirate Cycles sells.

Jim

Thanks, Jim, for such a comprehensive reply.
That 1/2" for frame clearance can be a lot on some frames.
Having said that, in my case, the air cleaner is closest to the frame, with only 10mm vertical clearance. (SBP low profile air filter and the RSE head isn't very tall.)

I'm not sure how much smaller in cc the RSE head is compared to the stock one, so as mentioned, I'll wait until someone bolts your head on a stock 66cc engine to compare compression pressures, just out of interest.

The stud length was a major issue for me with Tony's head. If it wasn't for the boys at Sick Bike Parts, I might still be trying to get 112mm x 8mm x 1.0mm studs.

Any idea of price yet, even a ballpark figure?

... Steve
 
Good price for all the work that's gone into this.
You won't get any complaints in that department, I wouldn't think.
Even here in Oz, with shipping, the price is comparable to Tony's.

... Steve
 
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